The invention further relates to a control device for such an arrangement for the purpose of transmitting data to an external diagnostic device.
Control devices, in particular comprising microprocessors (μP) or microcontrollers (μC), are commonly used in technology, such as in particular in motor vehicles, e.g. for drive control in power window lifters or in sliding/tilting sunroofs. In such applications it is often desired to transfer data from the control device, such as the contents of variables of the controller, in real time to a test computer for diagnostic purposes. In the case of an anti-trap protection algorithm for power window lifters or sunroof drives, however, this algorithm is difficult to diagnose via any standard interfaces that may be present, such as LIN and CAN, since the processes or computing models are highly dynamic and the bus connection provides too small a bandwidth, which is insufficient for the necessary data transmission. A further problem is that control devices are frequently not equipped with a bus termination. It is also often disadvantageous that the control device is installed in the associated entity, e.g. a motor vehicle door, and is difficult to access, while numerous components of the entity, such as paneling parts of a motor vehicle door in the case of a power window lifter, have to be disassembled in a time-consuming and laborious manner in order to gain access to the control device.
It has in fact already been proposed to provide a separate diagnostic interface on control devices, with a processor pin being brought out directly—i.e. without filter and without protective circuitry—in order thereby to make it easily accessible. However, this special solution cannot be provided in series production, since then there is an exceptionally great risk of damage to the control device via the pin, e.g. due to ESD (electrostatic discharge).
As a result there is the persistent problem that a control device that is installed in series in an associated entity, such as in a motor vehicle, is either difficult or impossible to access and therefore is scarcely able to be diagnosed. For diagnostic purposes, e.g. in the case of power window lifter control devices, the door paneling would have to be opened, which is often not allowed by the manufacturer, and the control device would have be to replaced or modified or resoldered.